Waves Lab

I.  Guiding Question: How do waves change when they move over an object?

II.HYPOTHESIS:  I think that when a wave moves over a smooth object the wave length will get shorter and the amplitude will get higher.  When it moves over a rougher object I think that the amplitude will get shorter and its wave length will get much shorter also.

III.  Exploration-
Materials:Tray, water, smoother clay, rough clay,

Procedure: Test how waves’ amplitudes and wave lengths change when they are forced to travel over a smooth surface and a rough surface. First I tested what the average amplitude was with no objects, then I tested how waves amplitude changes when they travel over a smooth object then over a rough object.
        

IV.  RECORD & ANALYZE
A.

Object	Amplitude
No object	44 mm
Smooth Object	52 mm
Rough Object	47 mm

B. On my first test I tested what the amplitude would be when there is no object to pass over. I put the water at approximately 17mm doing a sideways motion the amplitude was 44mm. Then I tested with a smooth piece of clay for the waves to go over with the same amount of water the amplitude was 52mm. On the last test I tested how the waves’ amplitude would change when it moved over a rough object the amplitude was 47mm. Out of all the tests it seemed that the waves amplitude was highest when forced to go over a smooth object. When the wave travelled over something it’s amplitude was higher than when it didn’t have to travel over any object. I think that my tests were mostly accurate because I tested many times before I settled on a definitive result. It was hard to see the amplitude because sometimes it would go high and sometimes it wouldn’t.


IV.  Concept Acquisition (CONCLUSION): Throughout all my tests I noticed a lot of things that I could never have predicted. My hypothesis was somewhat correct but when I saw that the rough object actually had a higher amplitude than without a barrier I was very surprised. I was right about the amplitude of the smooth abject because it went higher just like I predicted. The wave length was something that I couldn’t test when I started testing because of the way I was creating the waves, moving the tank side-to-side. The wave length was something I could only guess and would, therefore, be very inaccurate so in the end I really couldn’t test it. I think that my data was accurate and maybe was off by a millimeter or two but was in the right general area.
 

Wave Simulator

In science today we used a wave simulator to simulate different waves. It started out as just a faucet dripping one drop of water. You can control many things to make the waves different like frequency, amplitude, barriers, and even change the direction at which you look at the tank. You can look at water waves, light waves, or sound wave. I tested mainly how the waves would react when you change the amplitude and frequency. When the amplitude was very high then the waves were large, and when the amplitude was minimum then there were barely visible waves. When the frequency was very high then there were a lot of waves, when the frequency was low than a wave would only come once in a while. I then tested with barriers and added detectors, which tested the wave length of waves in certain places. I added 5 barriers at a time and that made the waves dissipate very quickly. The wave simulator was a fun thing to do and  is very interesting and educational.

Wave Interactions

In science class we tested how waves would react with no barriers, one barrier, and two barriers. First we tested how the waves would react when there is no barrier while moving the tray side to side. the motion created roughly 3-4 waves that moved from side to side. The waves moved from side to side passing through each other created many standing waves. The waves remained virtually unaffected by each other, if one of the waves was isolated then it would seem as though it was just reflecting from one side to another. When we tested it with one large barrier using the same back and forth motion it became a totally different outcome. When the wave hit the barrier in the middle of the tray half of it was absorbed by the clay instead of reflecting it like when it did with no barriers while the other side kept on going before it got hit by the wave going in the other direction. The last test we did was with two large barriers placed parallel to each other in the middle of the tray. In the last test we used the same motion to create the waves as in the previous two tests. When the wave hit the barriers most of its energy dissipated but a small part of the wave goes through the small hole in the middle of the two barriers creating diffraction. From our tests on how waves interact I've learned a lot. Waves reflect when they hit a barrier, they diffract when they travel through a small hole, when two hit each other it creates the illusion of a standing wave.